Optical architecture with hybrid on-silicon iii-v modulator

ABSTRACT

Embodiments may relate to an electronic device that includes a modulator to modulate an in-phase portion of an input signal and a quadrature portion of the input signal. The modulator may include a III-V material on a silicon substrate. In some embodiments, the III-V material may include, for example, indium phosphide (InP). Other embodiments may be described or claimed.

BACKGROUND

A silicon photonics-based high-speed modulator may be capable ofsupporting up to 400 gigabyte per second (Gb/s) based on aphase-amplitude modulation (PAM)-4 modulation scheme with four lanes ofup to 100 Gb/s each. In the case of coherent applications, the siliconphotonics modulator may be capable of supporting up to 64 gigabaud(GBaud) and 64 quadrature-amplitude modulation (QAM) high-ordermodulation, therefore supporting up to 600 Gb/s-per-lane with the use ofa coherent digital signal processor (DSP).

However, a silicon photonics-based modulator may include an intrinsiclimitation in areas such as a relatively high half-wave voltage(V_(pi)). For example, V_(pi) may be on the order of between 2 volts (V)and 5 V. The silicon photonics modulator may also have a bandwidth onthe order of between approximately 20 gigahertz (p) and approximately 40GHz for both direct PAM-4 and QAM-64 applications. Therefore, it may bedifficult to produce low-power and high baud rate devices for operationson the order of terabytes per second (Tb/s).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example optical architecture that includes a hybridmodulator, in accordance with various embodiments.

FIGS. 2a and 2b depict an example structure of a photonic transmitterthat includes a hybrid modulator, in accordance with variousembodiments.

FIG. 3 depicts an alternative example optical architecture that includesa hybrid modulator, in accordance with various embodiments.

FIG. 4 depicts an alternative example optical architecture that includesa hybrid modulator, in accordance with various embodiments.

FIG. 5 depicts an alternative example optical architecture that includesa hybrid modulator, in accordance with various embodiments.

FIG. 6 depicts an alternative example optical architecture that includesa hybrid modulator, in accordance with various embodiments.

FIG. 7 depicts an alternative example optical architecture that includesa hybrid modulator, in accordance with various embodiments.

FIG. 8 is a top view of a wafer and dies that may include a hybridmodulator, in accordance with various embodiments.

FIG. 9 is a block diagram of an example electrical device that mayinclude an optical architecture with a hybrid modulator, in accordancewith various embodiments.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, wherein like numeralsdesignate like parts throughout, and in which is shown by way ofillustration embodiments in which the subject matter of the presentdisclosure may be practiced. It is to be understood that otherembodiments may be utilized and structural or logical changes may bemade without departing from the scope of the present disclosure.Therefore, the following detailed description is not to be taken in alimiting sense.

For the purposes of the present disclosure, the phrase “A or B” means(A), (B), or (A and B). For the purposes of the present disclosure, thephrase “A, B, or C” means (A), (B), (C), (A and B), (A and C), (B andC), or (A, B and C).

The description may use perspective-based descriptions such astop/bottom, in/out, over/under, and the like. Such descriptions aremerely used to facilitate the discussion and are not intended torestrict the application of embodiments described herein to anyparticular orientation.

The description may use the phrases “in an embodiment,” or “inembodiments,” which may each refer to one or more of the same ordifferent embodiments. Furthermore, the terms “comprising,” “including,”“having,” and the like, as used with respect to embodiments of thepresent disclosure, are synonymous.

The term “coupled with,” along with its derivatives, may be used herein.“Coupled” may mean one or more of the following. “Coupled” may mean thattwo or more elements are in direct physical or electrical contact.However, “coupled” may also mean that two or more elements indirectlycontact each other, but yet still cooperate or interact with each other,and may mean that one or more other elements are coupled or connectedbetween the elements that are said to be coupled with each other. Theterm “directly coupled” may mean that two or elements are in directcontact.

In various embodiments, the phrase “a first feature[[formed/deposited/disposed/etc.]] on a second feature,” may mean thatthe first feature is formed/deposited/disposed/etc. over the featurelayer, and at least a part of the first feature may be in direct contact(e.g., direct physical or electrical contact) or indirect contact (e.g.,having one or more other features between the first feature and thesecond feature) with at least a part of the second feature.

Various operations may be described as multiple discrete operations inturn, in a manner that is most helpful in understanding the claimedsubject matter. However, the order of description should not beconstrued as to imply that these operations are necessarily orderdependent.

Embodiments herein may be described with respect to various Figures.Unless explicitly stated, the dimensions of the Figures are intended tobe simplified illustrative examples, rather than depictions of relativedimensions. For example, various lengths/widths/heights of elements inthe Figures may not be drawn to scale unless indicated otherwise.Additionally, some schematic illustrations of example structures ofvarious devices and assemblies described herein may be shown withprecise right angles and straight lines, but it is to be understood thatsuch schematic illustrations may not reflect real-life processlimitations which may cause the features to not look so “ideal” when anyof the structures described herein are examined, e.g., using scanningelectron microscopy (SEM) images or transmission electron microscope(TEM) images. In such images of real structures, possible processingdefects could also be visible, e.g., not-perfectly straight edges ofmaterials, tapered vias or other openings, inadvertent rounding ofcorners or variations in thicknesses of different material layers,occasional screw, edge, or combination dislocations within thecrystalline region, and/or occasional dislocation defects of singleatoms or clusters of atoms. There may be other defects not listed herebut that are common within the field of device fabrication.

As noted, a silicon photonics-based modulator may have limitations withrespect to areas such as V_(pi) or bandwidth. One option to addressthese limitations may be the inclusion of a III-V material-basedmodulator. One example III-V material may be, for example, indiumphosphide (InP). The III-V modulator may have higher modulationbandwidth, for example on the order of 65 GHz or more, and may supportgreater than 100 GBaud operation with multi Tb/s-per-lane coherenttransmission when used in conjunction with a coherent DSP. In addition,the V_(pi) of the III-V modulator may be made relatively low (e.g., lessthan 2V. For example, the V_(pi) of an III-V modulator may be betweenapproximately 1 and approximately 1.5 V), thereby reducing the powerconsumption of an optical transmission of which the III-V modulator is apart.

However, it may be difficult to produce a III-V material-based opticaltransmitter that is appropriate for coherent applications. For example,it may be difficult to achieve a high-yield/low-loss opticalpolarization splitter and rotator. Such a splitter or rotator mayrequire many process and regrowth steps to achieve complex functionsbased on a III-V system. As a result, the yield of such a process may berelatively low and have a relatively high manufacturing cost. It mayalso be challenging to produce such complex III—V based devices based onavailable fabrication processes.

Embodiments herein relate to resolving the above-described difficultiesby incorporating III-V materials such as InP onto a silicon photonicsplatform, thereby leveraging the strength of both platforms to producehigh-speed optical transmitters. Specifically, embodiments herein mayrelate to a transmitter architecture design that includes a modulatorwith an increased bandwidth capability. The bandwidth capability may bebased on a high-speed III-V epitaxial material that is grown to supporta high-speed/low-V_(pi) III-V material-based modulator. With such ahigh-speed epitaxial design, several dies that include an epitaxialIII-V layer may be placed onto a handling silicon wafer. The handlingwafer may be wafer-bonded onto a device silicon wafer. Subsequently, thehandling wafer and majority of the III-V epitaxial substrate and layersmay be removed, and one or more thin layers of active materials withsome number of optical confinement layers may remain.

On the silicon device wafer, the optical waveguides may be configured tosupport a Mach-Zehnder modulator (“MZM”) (e.g., the optical waveguidesmay diverge to allow for two concurrent optical paths for the opticalsignal as it traverses the modulator). The epitaxially-grown III-Vlayer(s) on the device wafer may be designed such that light emittedfrom a laser (either of the optical transmitter or coupled to theoptical transmitter) such that light may be gradually coupled and inputto the modulator herein it is modulated by the III-V materials, and themodulated light may then be gradually output and coupled to the outputwaveguide.

Embodiments herein may provide a number of advantages or benefits. Forexample, embodiments may include benefits from both III-V materials andsilicon photonics systems in a single modulator, which may be referredto herein as a “hybrid” modulator. As a result, embodiments may enableultra high-speed modulation in a silicon photonics platform that iscapable of supporting greater than 100 GBaud PAM applications perphysical channel and high-capacity coherent QAM applications beyond Tb/sper wavelength.

Turning to particular embodiments, configurations of the hybridmodulator may be similar to those of a MZM. Specifically, the hybridmodulator may include two different optical paths through the modulatorfor a single signal. Based on the interference pattern of the opticalpaths once they are recombined, data may be encoded into the opticalsignal to produce a modulated optical signal. In these particularembodiments, the MZM structure may include silicon waveguides on adevice wafer, and may further include III-V epitaxial materials whichmay be a part of the MZM structure. Particularly, the III-V materialsmay be in alignment with the input and output waveguides of themodulator. In some embodiments, the optical transmitter may include anumber of hybrid modulators which may be formed together for coherentapplications or non-coherent multiple-channel applications. As usedherein, a coherent application may refer to a single-wavelengthhigh-order QAM modulation scheme and a non-coherent application mayrefer to a multi-channel PAM modulation scheme.

FIG. 1 depicts an example optical transmitter architecture that includesa hybrid modulator, in accordance with various embodiments. It will beunderstood that FIGS. 1 and 2-7 are intended as highly simplifiedexamples of the architecture of an optical transmitter with respect tohow light may propagate through the optical transmitter. The depictedarchitectures do not depict various active or passive elements such asadditional logic, transistors, resistors, capacitors, etc. which may bepresent in real-world embodiments of the present disclosure.Additionally, although a certain number of structures or elements may bedepicted (e.g., a specific number of paths, modulators, splitters,inputs or outputs, monitor photodiodes (MPDs), amplifiers, etc.) otherembodiments may have more or fewer than are depicted herein, or elementsat different locations in the diagram. As one example, although someembodiments may depict elements such as amplifiers located both priorto, and subsequent to, the modulator, in some embodiments an amplifiermay not be present at the input or the output (or both) of themodulator. Additionally, various embodiments are depicted herein for thesake of discussion of various aspects of the present disclosure, but itwill be understood that the depictions are intended as non-limitingexamples. That is, other embodiments may include combinations of aspectsof various of the embodiments. It will also be understood that althoughsignals herein are described as “optical” signals, in some embodimentsthe signals may be some other type of photonic signal that has, forexample, a different frequency or wavelength.

FIG. 1 depicts an optical architecture 100. The optical architecture 100may have a number n of optical pathways 101 a, 101 b, 101 c, 101 n(collectively, “optical pathways 101”). In some embodiments, n may bebetween 1 and 32, while in other embodiments n may be higher than 32.The number n of optical pathways 101 may be based on factors such asdesign characteristics of the optical architecture 100, the type ofdevice in which the optical architecture 100 (and the correspondingoptical transmitter) may be used, etc. Each of the optical pathways 101may have a bandwidth of at least approximately 200 Gb/s or more. Thismay be compared to, for example, legacy MZMs which may have a bandwidthon the order of approximately 100 Gb/s.

As may be seen, respective ones of the optical pathways 101 may includea signal input 105 a/105 b/105 c/105 n (collectively, “signal inputs105”). The signal inputs 105 may be inputs wherein an optical signal maybe received. In some embodiments, the signal inputs 105 may receive anoptical signal from respective lasers (e.g., a different laser for eachoptical pathway 101) while in other embodiments two or more of thesignal inputs 105 may receive an optical signal from a single laserafter the signal has been split (e.g., by an optical splitter).

The optical signal may traverse from a signal input 105 to a splittersuch as splitters 110 a/110 b/110 c/110 n (collectively, “splitters110”). The splitters 110 may split the signal for input to themodulators 115 a/115 b/115 c/115 n (collectively, “modulators 115”). Themodulators 115 may be hybrid modulators as described herein.Particularly, the modulators 115 may include an epitaxially-depositedIII-V material such as InP on a silicon waveguide substrate as will bedescribed in greater detail with respect to FIGS. 2a and 2b . Aspreviously noted, the modulators 115 may be configured to act as a MZM,and so two optical pathways through respective ones of the modulators115 may be desirable for the operation as previously described.

After the optical signal has been modulated by one of modulators 115,the optical signal may then be recombined by a coupler such as couplers120 a/120 b/120 c/120 n (collectively, “couplers 120”) which mayrecombine the signal to form a modulated optical signal. The modulatedoptical signal may then be output by a signal output such as signaloutputs 125 a/125 b/125 c/125 n (collectively, “signal outputs 125”).

FIGS. 2a and 2b depict an example structure of a photonic transmitterthat includes a hybrid modulator, in accordance with variousembodiments. Specifically, FIG. 2a depicts a cross-sectional view ofsuch a structure, while FIG. 2b depicts an example top-down view of thestructure. The modulator 215 may be similar to, for example, one ofmodulators 115, and may be coupled with a substrate 203.

The substrate 203 may include a plurality of layers such as the siliconwaveguide 213, a buried oxide layer 218, and a dielectric material 223.The substrate 203 may be, for example, considered to be a cored orcoreless substrate. The substrate 203 may include one or more layers ofthe dielectric material 223. The dielectric material 223 may be organicor inorganic and may be, or include, silicon, a build-up film (ABF) orsome other type of dielectric material. The substrate 203 may furtherinclude one or more conductive elements such as vias, pads, traces,microstrips, striplines, etc. Various of the conductive elements may beinternal to, or on the surface of, the substrate 203. Generally, theconductive elements may allow for the routing of signals through thesubstrate 203, between elements that are coupled to the substrate 203,etc. In some embodiments the substrate 203 may be, for example, aprinted circuit board (PCB), an interposer, a motherboard, or some othertype of substrate.

As noted, the substrate 203 may include a silicon waveguide 213. Thewaveguide 213 may be configured to propagate a signal such as an opticalsignal 228 through the waveguide 213. In this embodiment, the siliconwaveguide 213 may be or may include silicon, however in otherembodiments the waveguide may be or include silicon nitride or someother material. As previously noted, in some embodiments the opticalsignal 228 may be in a short wavelength spectrum (e.g., having awavelength between approximately 1200 nanometers (nm) and approximately1400 nm). In other embodiments, the optical signal 228 may have adifferent wavelength such as in a longer wavelength spectrum (i.e.,between approximately 1500 nm to 1600 nm. The specific wavelength of theoptical signal 228 may be based on a factor such as the use case towhich the modulator 215 may be put, design considerations, materialsused, etc. As may be seen, the waveguide 213 may be positioned in aportion of an optical dielectric material 229 which may be the same typeof dielectric material, or a different type of dielectric material, asdielectric material 223.

The substrate 203 may further include the buried oxide layer 218positioned between the silicon waveguide 213. The buried oxide layer 218may be formed of an optical dielectric such as, for example, siliconoxide (SiO₂). Specifically, the buried oxide layer 218 may be to preventleakage of the optical signal 228 from the silicon waveguide 213 intothe dielectric material 223.

The modulator 215 may include a III-V material 208. In some embodiments,the III-V material 208 may be, or include InP. Specifically, the III-Vmaterial 208 may be a quantum well (QW) or multiple quantum well (MQW)material such as an indium aluminum gallium arsenide (InAlGaAs)epitaxial layer material on InP. Specifically, the InAlGaAs material maybe epitaxially grown on one or more layers of InP. The QW material may,for example, as a way of illustration only, include a range of thirty tothirty-five layers of InAlGaAs wells in layers with an identicalthickness of approximately in the range of several nanometers such asfrom 5 to 7 nm for each QW; and alternate layers of InAlAs barriers withan identical thickness of between approximately from 8 to 10 nm for eachof the barriers-. Generally, the number of the barriers may be equals tothe number of the QWs plus one additional layer. The wells and barriersmay alternate in the QW structure. In other embodiments, a QW materialmay be, for example, thirty-two layers of InAlGaAs wells andthirty-three layers of InAlAs barriers, wherein the wells and barriersalternate. In other embodiments, the III-V material 208 may be a quantumdot (QD) material or some other type of III-V material.

As may be seen, the III-V material 208 of the modulator 215 may bephysically or communicatively coupled with the silicon waveguide 213. Asthe optical signal 228 propagates through the silicon waveguide 213, itmay transfer into the modulator 215 where it may be modulated to includedata that is supplied by a high-speed data source such as a processor, aprocessor core, a central processing unit (CPU), a high-speed driverthat amplifies the incoming data signal to a proper level to drive themodulator, and etc. The now-modulated optical signal 228 may then beoutput from the modulator 215 back into the silicon waveguide 213 asshown.

As shown in FIG. 2b , it will be noted that in some embodiments themodulator 215, and particularly the III-V material 208, may be taperedin such a fashion as to facilitate adiabatic transference of the opticalsignal 228 between the III-V material 208 and the silicon waveguide 213.In some embodiments, the taper of the III-V material 208 may be in az-direction (i.e., up and down with respect to the orientation of FIG.2, not shown). In other embodiments, the taper of the III-V material 208may additionally or alternatively be in a direction perpendicular to thedirection of travel of the optical signal and parallel to the siliconwaveguide 213. That is, the III-V material 208 may be tapered as shownin FIG. 2b . In some embodiments, the taper may be such that the III-Vmaterial 208 comes to a point as seen in a top-down view of themodulator 215. Other embodiments may have different types or degrees oftapers.

Additionally, as may be noted, in some embodiments the modulator 215 mayhave a greater width than the width of the silicon waveguide 213.However, in other embodiments the width of the modulator 215 may bedifferent than as depicted with respect to the width of the siliconwaveguide 213. For example, in some embodiments the modulator 215 mayhave a same width as, or be narrower than, the silicon waveguide 213. Itwill also be noted that the specific degree of taper, the type of taper,or even the existence of the taper may be different in differentembodiments. It will also be noted that FIGS. 2a and 2b are intended ashighly simplified example embodiments, and other embodiments may haveadditional elements such as additional active, passive, or conductiveelements, overmold material, etc. Other variations may be present inother embodiments.

FIGS. 3-7 depict alternative example optical architectures that mayinclude a hybrid modulator, in accordance with various embodiments. Itwill be understood that FIGS. 3-7 are intended as highly simplifiedexample Figures and may not show each and every element which may bepresent in such an architecture. Rather, the Figures are intended toshow examples of various concepts which may be applied to real-worldembodiments. Such real-world embodiments may include additional elementssuch as active or passive components, conductive elements, etc.Additionally, it will be noted that each and every element of FIGS. 3-7may not be enumerated for the sake of lack of redundancy or clutter ofthe Figures, however (unless expressly noted otherwise), it may begenerally assumed that elements that share the same generalshape/shading/location as enumerated and discussed elements may havesimilar features or characteristics

Specifically, FIG. 3 depicts an example optical architecture 300 whichmay be similar to, and share one or more characteristics with, opticalarchitecture 100. The optical architecture 300 may include a number ofoptical paths 301 a, 301 b, 301 c, and 301 d (collectively, “opticalpaths 301”) which may be similar to, and share one or morecharacteristics with, optical paths 101.

However, as opposed to FIG. 1 where respective ones of the optical paths101 may include an individual modulator 115, the optical architecture300 may include a single modulator 315 which may span two or more of theoptical paths 301 as shown in FIG. 3. Such a modulator 315 may beenabled by, for example, include a plurality of waveguides such aswaveguide 213 in a single substrate such as substrate 203.

FIG. 4 depicts an example optical architecture 400 which may be similarto, and share one or more characteristics with, optical architectures100 or 300. The optical architecture 400 may include a number of opticalpaths 401 a, 401 b, 401 c, and 401 d (collectively, “optical paths 401”)which may be similar to, and share one or more characteristics with,optical paths 101 or 301.

However, in some embodiments the modulator 315 may result in some amountof signal loss of the optical signal as it traverses the modulator. Sucha signal loss may be based on, for example, the transition from thesilicon waveguide to the modulator (or from the modulator to the siliconwaveguide), the act of modulation, or some other factors. Therefore, insome embodiments it may be desirable to amplify the signal either priorto, or subsequent to, the modulator 315. As shown in FIG. 4, the opticalarchitecture may include a plurality of amplifiers 430 a and 430 b(collectively, “amplifiers 430”). In some embodiments, one or both ofthe amplifiers 430 may include a material or structure that is similarto that of the modulator 315. Specifically, in some embodiments one orboth of the amplifiers 430 may include a III-V material positioned on asilicon substrate such as substrate 203. The general shape orconfiguration of such an amplifier may be similar to that shown withrespect to modulator 215. For example, one or both of the amplifiers 430may include a tapered portion at one or both ends of the amplifier. Inother embodiments, one or both of the amplifiers 430 may be a differenttype of amplifier. In some embodiments, the III-V material of one orboth of the amplifiers 430 may be or include InP as described above in aMQW structure, while in other embodiments one or both of the amplifiers430 may additionally or alternatively include a QD material andstructure or some other types of III-V material.

More generally, the amplifiers 430 may include a III-V material 208. Insome embodiments, the III-V material 208 may be, or may include, InP.Specifically, the III-V material 208 may be a QW or MQW material such asan InAlGaAs epitaxial layer material on InP. Specifically, the InAlGaAsmaterial may be epitaxially grown on one or more layers of InP. The QWmaterial may, for example, as a way of illustration only, include threelayers of InAlGaAs wells with a thickness of approximately 7 nm for eachof the three quantum wells; and alternate layers of InAlAs barriers witha thickness of approximately 10 nm for each of the four barriers. Thewells and barriers may alternate in the QW structure. In otherembodiments, a QW material may be, for example, five layers of InAlGaAswells and six layers of InAlAs barriers, wherein the wells and barriersalternate.

It will be understood that, as noted above, FIG. 4 is intended as anexample embodiment. In some embodiments, one or both of the amplifiers430 may be positioned at a different part of the optical architecture400. For example, amplifier 430 a may be positioned between signal input105 a and splitter 110 a. Additionally or alternatively, amplifier 430 bmay be positioned between coupler 120 a and signal output 125 a. In someembodiments, one or both of amplifiers 430 may not be present in theoptical architecture 400. In some embodiments an amplifier 430 may notspan each of the optical paths 401, but rather may be span only a singleoptical path 401, or a portion of an optical path 401.

FIG. 5 depicts a more complicated architecture which may be used for anoptical architecture 500. Generally, the optical architecture 500 may besimilar to, and share one or more characteristics with, one or more ofoptical architectures 100, 300, or 400. For the sake of ease ofillustration, elements of optical architecture 100 (or other opticalarchitectures here) such as a splitter 110 or a coupler 120 may not beshown in FIG. 5 (or other Figures such as FIGS. 6 and 7). However, oneof skill in the art will recognize from FIG. 5 that such elements maystill be present, and where those elements may be positioned.

The optical architecture 500 may include a signal input 505, signaloutput 525, modulator 515, and amplifiers 530 a/530 b (collectively,“amplifiers 530”) which may be respectively similar to, and share one ormore characteristics with, signal input 105, signal output 125,modulator 115, and amplifiers 430 a/430 b.

The optical signal may be provided by the signal input, where it maythen be split amongst two optical paths 550 a and 550 b (collectively“optical paths 550”). Respective ones of the optical paths 550 may thenbe split into different phases. For example, optical paths 555 a may bein-plane portions of the optical signal, whereas optical paths 555 b maybe quadrature portions of the optical signal. In some embodiments,optical paths 555 b may include a phase shifter 545 which may shift theoptical signal to a quadrature signal. The various signals may then beinput to one or more of the amplifiers 530 and modulator 515 where thesignal may be modulated or amplified.

The modulator 515 may output a plurality of modulated optical signalsonto in-phase output paths 560 a and quadrature output paths 560 b.Similarly to the input side of the optical architecture, there may be anin-phase and a quadrature output paths 560 a/560 b for both paths 550 ofthe optical signal. The modulated optical signals may be combined fromthe in-phase output path 560 a and the quadrature output path 560 b andprovided output paths 565 a and 565 b. The modulated optical signalsfrom output paths 565 a and 565 b may be input to a polarization rotatorand beam combiner (PRBC) 540 where one of the signals from an outputpath (e.g., the modulated optical signal from output path 565 a) may berotated by 90 degrees such that the two modulated output signals havedifferent polarizations (which may be referred to, for example, as“x-polarization” and “y-polarization”). The polarized and modulatedoutput signals may then be combined to a single modulated optical signalthat is provided to signal output 525.

As may be seen in FIG. 5, the optical architecture 500 may furtherinclude a number of monitor photodiodes (MPDs) 535 at various pointalong the output side of the optical architecture 500. The MPDs 535 maybe used to monitor the optical power level from either the main outputarm or the complimentary arm of each of the interferometers by the useof a coupler-based optical tap from the main output arm or thecomplimentary arm, and the additional MPD at the tap port. The MPD maybe or include a silicon germanium structure or the hybrid III-V diebonded to the silicon wafer at the location of interest.

It will be understood that, similarly to other embodiments describedherein, the embodiment of FIG. 5 is intended as an example embodiment,and other embodiments may vary from those depicted. For example, asnoted in some embodiments certain of the amplifiers 530 may be missing,or additionally/alternatively in a different location (e.g., at 550 a/b,555 a/b, 560 a/b, 565 a/b, etc.). In some embodiments, one or more ofthe modulator 515 or the amplifiers 530 may not span each of the opticalpaths, but rather there may be a different modulator or amplifier foreach of the various input or output paths, phase-related optical paths,or even between different branches of the a MZM. Additionally, on theoutput side of the optical architecture 500, the MPDs 535 may bearranged in a different configuration, or there may be a differentnumber of MPDs 535 than are depicted in FIG. 5. Other variations may bepresent in other embodiments.

FIG. 6 depicts an alternative example optical architecture 600 which maybe generally similar to, and share one or more characteristics with,optical architecture 500 or some other optical architecture herein.Amongst other things, FIG. 6 may depict an optical architecture 600 withamplifiers 630 a and 630 b (collectively referred to as “amplifiers630”) which may be generally similar to, and share one or morecharacteristics with, amplifiers 430 a and 430 b or some other amplifierherein. However, as may be seen by comparing the optical architecture600 with optical architecture 500, the amplifiers 630 may be at adifferent location within the signal path of the optical architecture600. Specifically, amplifiers 630 a may be located in the optical paths550 a and 550 b, while amplifier 630 b may be located at output paths565 a and 565 b. As previously noted, it will be realized that this isan example embodiment and other embodiments may vary. For example, thetwo amplifiers 630 a may be replaced by a single amplifier that spansboth of the optical paths 550 a and 550 b. Similarly, the singleamplifier 630 b may be replaced by separate amplifiers at respectiveones of the output paths 565 a and 565 b. In some embodiments, theinput-side amplifier may be as shown with respect to amplifier 530 a,while the output-side amplifier may be as shown with respect toamplifier 630 b, or vice-versa, or some combination thereof.

FIG. 7 depicts an alternative example optical architecture 700 which maybe generally similar to, and share one or more characteristics with,optical architecture 500 or some other optical architecture herein. Asmay be seen, in order to illustrate one example concept related to thepresent disclosure, optical architecture 700 may not include one or moreof the amplifiers such as amplifiers 530 a or 530 b.

As may be seen, the optical architecture 700 may depict variations onmodulator configuration which may be present in various embodiments.Specifically, the optical architecture 700 may include a variety ofmodulators 715 a, 715 b, and 715 c (collectively referred to as“modulators 715”) which may be similar to, and share one or morecharacteristics with, modulators 115 or some other modulator herein. Asmay be seen, a separate III—V based modulator die 715 a may be presenton each of the two optical paths of a MZM. As another example, a singleIII—V based modulator die 715 b may span both optical paths of a MZM. Asanother example, a single III-V based modulator die 715 c may span aplurality of MZMs, which works in conjunction together with each of theunderlining MZM silicon waveguides to form a hybrid MZM in each of thesegments. Other embodiments may have other variations.

As noted, FIGS. 1-7 are intended as highly simplified examples, andcertain Figures may have certain characteristics that are featured forthe sake of discussion herein. However, it will be understood thatfeatures of various of the Figures may be combined with features ofothers of the Figures.

FIG. 8 is a top view of a wafer 1500 and dies 1502 that may include oneor more hybrid modulators, or may be included in an IC package includingone or more hybrid modulators in accordance with various embodiments.The wafer 1500 may be composed of semiconductor material and may includeone or more dies 1502 having IC structures formed on a surface of thewafer 1500. Each of the dies 1502 may be a repeating unit of asemiconductor product that includes a suitable IC. After the fabricationof the semiconductor product is complete, the wafer 1500 may undergo asingulation process in which the dies 1502 are separated from oneanother to provide discrete “chips” of the semiconductor product. Thedie 1502 may include one or more hybrid modulators, one or moretransistors or supporting circuitry to route electrical signals to thetransistors, or some other IC component. In some embodiments, the wafer1500 or the die 1502 may include a memory device (e.g., a random-accessmemory (RAM) device, such as a static RAM (SRAM) device, a magnetic RAM(MRAM) device, a resistive RAM (RRAM) device, a conductive-bridging RAM(CBRAM) device, etc.), a logic device (e.g., an AND, OR, NAND, or NORgate), or any other suitable circuit element. Multiple ones of thesedevices may be combined on a single die 1502. For example, a memoryarray formed by multiple memory devices may be formed on a same die 1502as a processing device (e.g., the processing device 1802 of FIG. 9) orother logic that is configured to store information in the memorydevices or execute instructions stored in the memory array.

FIG. 9 is a block diagram of an example electrical device 1800 that mayinclude one or more hybrid modulators, in accordance with any of theembodiments disclosed herein. For example, any suitable ones of thecomponents of the electrical device 1800 may include one or more of theIC device assemblies, IC packages, IC devices, or dies 1502 disclosedherein. A number of components are illustrated in FIG. 9 as included inthe electrical device 1800, but any one or more of these components maybe omitted or duplicated, as suitable for the application. In someembodiments, some or all of the components included in the electricaldevice 1800 may be attached to one or more motherboards. In someembodiments, some or all of these components are fabricated onto asingle system-on-a-chip (SoC) die.

Additionally, in various embodiments, the electrical device 1800 may notinclude one or more of the components illustrated in FIG. 9, but theelectrical device 1800 may include interface circuitry for coupling tothe one or more components. For example, the electrical device 1800 maynot include a display device 1806, but may include display deviceinterface circuitry (e.g., a connector and driver circuitry) to which adisplay device 1806 may be coupled. In another set of examples, theelectrical device 1800 may not include an audio input device 1824 or anaudio output device 1808, but may include audio input or output deviceinterface circuitry (e.g., connectors and supporting circuitry) to whichan audio input device 1824 or audio output device 1808 may be coupled.

The electrical device 1800 may include a processing device 1802 (e.g.,one or more processing devices). As used herein, the term “processingdevice” or “processor” may refer to any device or portion of a devicethat processes electronic data from registers and/or memory to transformthat electronic data into other electronic data that may be stored inregisters and/or memory. The processing device 1802 may include one ormore DSPs, application-specific integrated circuits (ASICs), CPUs,graphics processing units (GPUs), cryptoprocessors (specializedprocessors that execute cryptographic algorithms within hardware),server processors, or any other suitable processing devices. Theelectrical device 1800 may include a memory 1804, which may itselfinclude one or more memory devices such as volatile memory (e.g.,dynamic RAM (DRAM)), nonvolatile memory (e.g., read-only memory (ROM)),flash memory, solid state memory, and/or a hard drive. In someembodiments, the memory 1804 may include memory that shares a die withthe processing device 1802. This memory may be used as cache memory andmay include embedded DRAM (eDRAM) or spin transfer torque magnetic RAM(STT-MRAM).

In some embodiments, the electrical device 1800 may include acommunication chip 1812 (e.g., one or more communication chips). Forexample, the communication chip 1812 may be configured for managingwireless communications for the transfer of data to and from theelectrical device 1800. The term “wireless” and its derivatives may beused to describe circuits, devices, systems, methods, techniques,communications channels, etc., that may communicate data through the useof modulated electromagnetic radiation through a nonsolid medium. Theterm does not imply that the associated devices do not contain anywires, although in some embodiments they might not.

The communication chip 1812 may implement any of a number of wirelessstandards or protocols, including but not limited to Institute forElectrical and Electronic Engineers (IEEE) standards including Wi-Fi(IEEE 802.11 family), IEEE 802.16 standards (e.g., IEEE 802.16-2005Amendment), Long-Term Evolution (LTE) project along with any amendments,updates, and/or revisions (e.g., advanced LTE project, ultra mobilebroadband (UMB) project (also referred to as “3GPP2”), etc.). IEEE802.16 compatible Broadband Wireless Access (BWA) networks are generallyreferred to as WiMAX networks, an acronym that stands for WorldwideInteroperability for Microwave Access, which is a certification mark forproducts that pass conformity and interoperability tests for the IEEE802.16 standards. The communication chip 1812 may operate in accordancewith a Global System for Mobile Communication (GSM), General PacketRadio Service (GPRS), Universal Mobile Telecommunications System (UMTS),High-Speed Packet Access (HSPA), Evolved HSPA (E-HSPA), or LTE network.The communication chip 1812 may operate in accordance with Enhanced Datafor GSM Evolution (EDGE), GSM EDGE Radio Access Network (GERAN),Universal Terrestrial Radio Access Network (UTRAN), or Evolved UTRAN(E-UTRAN). The communication chip 1812 may operate in accordance withCode Division Multiple Access (CDMA), Time Division Multiple Access(TDMA), Digital Enhanced Cordless Telecommunications (DECT),Evolution-Data Optimized (EV-DO), and derivatives thereof, as well asany other wireless protocols that are designated as 3G, 4G, 5G, andbeyond. The communication chip 1812 may operate in accordance with otherwireless protocols in other embodiments. The electrical device 1800 mayinclude an antenna 1822 to facilitate wireless communications and/or toreceive other wireless communications (such as AM or FM radiotransmissions).

In some embodiments, the communication chip 1812 may manage wiredcommunications, such as electrical, optical, or any other suitablecommunication protocols (e.g., the Ethernet). As noted above, thecommunication chip 1812 may include multiple communication chips. Forinstance, a first communication chip 1812 may be dedicated toshorter-range wireless communications such as Wi-Fi or Bluetooth, and asecond communication chip 1812 may be dedicated to longer-range wirelesscommunications such as global positioning system (GPS), EDGE, GPRS,CDMA, WiMAX, LTE, EV-DO, or others. In some embodiments, a firstcommunication chip 1812 may be dedicated to wireless communications, anda second communication chip 1812 may be dedicated to wiredcommunications.

The electrical device 1800 may include battery/power circuitry 1814. Thebattery/power circuitry 1814 may include one or more energy storagedevices (e.g., batteries or capacitors) and/or circuitry for couplingcomponents of the electrical device 1800 to an energy source separatefrom the electrical device 1800 (e.g., AC line power).

The electrical device 1800 may include a display device 1806 (orcorresponding interface circuitry, as discussed above). The displaydevice 1806 may include any visual indicators, such as a heads-updisplay, a computer monitor, a projector, a touchscreen display, aliquid crystal display (LCD), a light-emitting diode display, or a flatpanel display.

The electrical device 1800 may include an audio output device 1808 (orcorresponding interface circuitry, as discussed above). The audio outputdevice 1808 may include any device that generates an audible indicator,such as speakers, headsets, or earbuds.

The electrical device 1800 may include an audio input device 1824 (orcorresponding interface circuitry, as discussed above). The audio inputdevice 1824 may include any device that generates a signalrepresentative of a sound, such as microphones, microphone arrays, ordigital instruments (e.g., instruments having a musical instrumentdigital interface (MIDI) output).

The electrical device 1800 may include a GPS device 1818 (orcorresponding interface circuitry, as discussed above). The GPS device1818 may be in communication with a satellite-based system and mayreceive a location of the electrical device 1800, as known in the art.

The electrical device 1800 may include another output device 1810 (orcorresponding interface circuitry, as discussed above). Examples of theother output device 1810 may include an audio codec, a video codec, aprinter, a wired or wireless transmitter for providing information toother devices, or an additional storage device.

The electrical device 1800 may include another input device 1820 (orcorresponding interface circuitry, as discussed above). Examples of theother input device 1820 may include an accelerometer, a gyroscope, acompass, an image capture device, a keyboard, a cursor control devicesuch as a mouse, a stylus, a touchpad, a bar code reader, a QuickResponse (QR) code reader, any sensor, or a radio frequencyidentification (RFID) reader.

The electrical device 1800 may have any desired form factor, such as ahandheld or mobile electrical device (e.g., a cell phone, a smart phone,a mobile internet device, a music player, a tablet computer, a laptopcomputer, a netbook computer, an ultrabook computer, a personal digitalassistant (PDA), an ultra mobile personal computer, etc.), a desktopelectrical device, a server device or other networked computingcomponent, a printer, a scanner, a monitor, a set-top box, anentertainment control unit, a vehicle control unit, a digital camera, adigital video recorder, or a wearable electrical device. In someembodiments, the electrical device 1800 may be any other electronicdevice that processes data.

Examples of Various Embodiments

Example 1 includes an electronic device comprising: a signal input toprovide an input signal; a splitter to separate the input signal into anin-phase portion of the input signal and a quadrature portion of theinput signal; a modulator to modulate the in-phase portion of the inputsignal and the quadrature portion of the input signal to respectivelyproduce a modulated in-phase portion of the input signal and a modulatedquadrature portion of the input signal, wherein the modulator includes aIII-V material on a silicon substrate; and a coupler to couple themodulated in-phase portion of the input signal and the modulatedquadrature portion of the input signal to form an output signal.

Example 2 includes the electronic device of example 1, wherein the III-Vmaterial includes InP.

Example 3 includes the electronic device of examples 1 or 2, furthercomprising an amplifier communicatively coupled with the modulator.

Example 4 includes the electronic device of example 3, wherein theamplifier is to amplify the input signal, the in-phase portion of theinput signal, or the quadrature portion of the input signal.

Example 5 includes the electronic device of example 3, wherein theamplifier is to amplify the modulated in-phase portion of the inputsignal, the modulated quadrature portion of the input signal, or theoutput signal.

Example 6 includes the electronic device of examples 1 or 2, wherein theelectronic device further comprises: a second signal input to provide asecond input signal; a second splitter to separate the second inputsignal into an in-phase portion of the second input signal and aquadrature portion of the second input signal; and wherein the modulatoris to modulate the in-phase portion of the second input signal and thequadrature portion of the second input signal.

Example 7 includes the electronic device of example 6, wherein the firstinput signal is a first polarization of an optical signal, and thesecond input signal is a second polarization of the optical signal.

Example 8 includes the electronic device of example 7, wherein theelectronic device further includes a PRBC communicatively coupled withthe coupler.

Example 9 includes an electronic device comprising: a splitter toseparate an input signal into an in-phase portion and a quadratureportion; a modulator to modulate the in-phase portion of the inputsignal to produce a modulated in-phase portion, wherein the modulatorincludes InP on a silicon waveguide; and a coupler to couple themodulated in-phase portion and a modulated quadrature portion of theinput signal to produce an output signal.

Example 10 includes the electronic device of example 9, wherein themodulator is a MZM.

Example 11 includes the electronic device of example 9, furthercomprising a power source that is to supply a half-wave voltage to themodulator, wherein the half-wave voltage is less than 2 volts.

Example 12 includes the electronic device of any of examples 9-11,further comprising a second modulator to modulate the quadrature portionof the input signal to produce a modulated quadrature portion, whereinthe second modulator includes InP on a silicon waveguide.

Example 13 includes the electronic device of any of examples 9-11,wherein the modulator is further to modulate the quadrature portion ofthe input signal to produce a modulated quadrature portion.

Example 14 includes the electronic device of any of examples 9-11,wherein the modulator is further to modulate the in-phase portion of asecond input signal to produce a second modulated in-phase portion.

Example 15 includes the electronic device of any of examples 9-11,wherein the electronic device further includes an amplifiercommunicatively coupled with the modulator.

Example 16 includes a MZM comprising: a signal input to receive anunmodulated optical signal; a signal output to output a modulatedoptical signal that is based on the unmodulated optical signal; asilicon waveguide on a substrate to facilitate transference of theoptical signal between the signal input and the signal output; and aIII-V material physically coupled with the silicon waveguide.

Example 17 includes the MZM of example 16, wherein the modulated opticalsignal is based on a modulated in-phase component of the unmodulatedoptical signal or a modulated quadrature component of the unmodulatedoptical signal.

Example 18 includes the MZM of example 16, wherein the modulated opticalsignal is based on a modulated in-phase component of the unmodulatedoptical signal and a modulated quadrature component of the unmodulatedoptical signal.

Example 19 includes the MZM of any of examples 16-18, wherein the MZMfurther comprises: a second signal input to receive a second unmodulatedoptical signal; and a second signal output to output a second modulatedoptical signal that is based on the second unmodulated optical signal.

Example 20 includes the MZM of any of examples 16-18, wherein the III-Vmaterial includes InP.

Various embodiments may include any suitable combination of theabove-described embodiments including alternative (or) embodiments ofembodiments that are described in conjunctive form (and) above (e.g.,the “and” may be “and/or”). Furthermore, some embodiments may includeone or more articles of manufacture (e.g., non-transitorycomputer-readable media) having instructions, stored thereon, that whenexecuted result in actions of any of the above-described embodiments.Moreover, some embodiments may include apparatuses or systems having anysuitable means for carrying out the various operations of theabove-described embodiments.

The above description of illustrated embodiments, including what isdescribed in the Abstract, is not intended to be exhaustive or limitingas to the precise forms disclosed. While specific implementations of,and examples for, various embodiments or concepts are described hereinfor illustrative purposes, various equivalent modifications may bepossible, as those skilled in the relevant art will recognize. Thesemodifications may be made in light of the above detailed description,the Abstract, the Figures, or the claims.

1. An electronic device comprising: a signal input to provide an inputsignal; a splitter to separate the input signal into an in-phase portionof the input signal and a quadrature portion of the input signal; amodulator to modulate the in-phase portion of the input signal and thequadrature portion of the input signal to respectively produce amodulated in-phase portion of the input signal and a modulatedquadrature portion of the input signal, wherein the modulator includes aIII-V material on a silicon substrate; and a coupler to couple themodulated in-phase portion of the input signal and the modulatedquadrature portion of the input signal to form an output signal.
 2. Theelectronic device of claim 1, wherein the III-V material includes indiumphosphide (InP).
 3. The electronic device of claim 1, further comprisingan amplifier communicatively coupled with the modulator.
 4. Theelectronic device of claim 3, wherein the amplifier is to amplify theinput signal, the in-phase portion of the input signal, or thequadrature portion of the input signal.
 5. The electronic device ofclaim 3, wherein the amplifier is to amplify the modulated in-phaseportion of the input signal, the modulated quadrature portion of theinput signal, or the output signal.
 6. The electronic device of claim 1,wherein the electronic device further comprises: a second signal inputto provide a second input signal; a second splitter to separate thesecond input signal into an in-phase portion of the second input signaland a quadrature portion of the second input signal; and wherein themodulator is to modulate the in-phase portion of the second input signaland the quadrature portion of the second input signal.
 7. The electronicdevice of claim 6, wherein the first input signal is a firstpolarization of an optical signal, and the second input signal is asecond polarization of the optical signal.
 8. The electronic device ofclaim 7, wherein the electronic device further includes a polarizationrotator and beam combiner (PRBC) communicatively coupled with thecoupler.
 9. An electronic device comprising: a splitter to separate aninput signal into an in-phase portion and a quadrature portion; amodulator to modulate the in-phase portion of the input signal toproduce a modulated in-phase portion, wherein the modulator includesindium phosphide (InP) on a silicon waveguide; and a coupler to couplethe modulated in-phase portion and a modulated quadrature portion of theinput signal to produce an output signal.
 10. The electronic device ofclaim 9, wherein the modulator is a Mach-Zehnder modulator (MZM). 11.The electronic device of claim 9, further comprising a power source thatis to supply a half-wave voltage to the modulator, wherein the half-wavevoltage is less than 2 volts.
 12. The electronic device of claim 9,further comprising a second modulator to modulate the quadrature portionof the input signal to produce a modulated quadrature portion, whereinthe second modulator includes InP on a silicon waveguide.
 13. Theelectronic device of claim 9, wherein the modulator is further tomodulate the quadrature portion of the input signal to produce amodulated quadrature portion.
 14. The electronic device of claim 9,wherein the modulator is further to modulate the in-phase portion of asecond input signal to produce a second modulated in-phase portion. 15.The electronic device of claim 9, wherein the electronic device furtherincludes an amplifier communicatively coupled with the modulator.
 16. AMach-Zehnder modulator (MZM) comprising: a signal input to receive anunmodulated optical signal; a signal output to output a modulatedoptical signal that is based on the unmodulated optical signal; asilicon waveguide on a substrate to facilitate transference of theoptical signal between the signal input and the signal output; and aIII-V material physically coupled with the silicon waveguide.
 17. TheMZM of claim 16, wherein the modulated optical signal is based on amodulated in-phase component of the unmodulated optical signal or amodulated quadrature component of the unmodulated optical signal. 18.The MZM of claim 16, wherein the modulated optical signal is based on amodulated in-phase component of the unmodulated optical signal and amodulated quadrature component of the unmodulated optical signal. 19.The MZM of claim 16, wherein the MZM further comprises: a second signalinput to receive a second unmodulated optical signal; and a secondsignal output to output a second modulated optical signal that is basedon the second unmodulated optical signal.
 20. The MZM of claim 16,wherein the III-V material includes indium phosphide (InP).